The Earth's magnetic field intensity is about 0.5 to 0.6 gauss and has a component parallel to the Earth's surface that always points toward magnetic north. This field can be approximated with a dipole model—the field always points north, but the angle of the field relative to the surface of the Earth changes from horizontal at the equator to sub-horizontal (i.e., “down” toward the ground) in the northern hemisphere and supra-horizontal (i.e., “up” toward the air) in the southern hemisphere. In all cases, the horizontal direction of the Earth's field points toward magnetic north and is used to determine compass direction.
Magnetic sensors have been in use for well over 2,000 years, primarily used to sense the Earth's magnetic field for direction finding or navigation. Today, magnetic sensors are still a primary means of navigation and many other uses have evolved. As a result, magnetic sensors may be found in medical, laboratory, and electronic instruments; weather buoys; virtual reality systems; and a variety of other systems.
Modern consumer and commercial electronic equipment design has generally involved the consolidation of numerous disparate functions into a single device and the evolution of devices of increasingly diminutive scale. Small devices and devices that incorporate numerous functions require their internal components to be as small as possible. The desire to incorporate wayfinding and navigation technology into such compact devices requires the requisite 2- and 3-dimensional sensors, for example magnetic sensors and/or tilt sensors, to be of minimum height in the Z-axis (i.e., out of the plane of the printed circuit board (PCB)). Mounting a vertical sensor along the Z-axis is a challenge for the semiconductor assembly industry, especially for applications that have space limitations. Current methods fail to mount vertical (Z-axis) sensors for applications with limited space and cost sensitive, high volume, standard PCB processes.
Therefore, a need exists for mounting sensors orthogonally to other sensors mounted in the plane of a printed circuit board, said orthogonally mounted sensors measuring forces or magnetic fields on the Z-axis. In particular, a need exists for mounting of orthogonal sensors in a low profile manner in, for example, cell phone and other consumer and commercial applications. Such needs should be filled by applications that are cost sensitive, high volume, and easily adaptable to common PCB assembly processes.